In the prior art, self-propelled machines that can be steered, or directionally controlled, more particularly, construction machines that are driven slowly, are controlled depending on the current steering angle of a set of steerable wheels.
It is known, for instance, to apply remote directional control to such a machine with the aid of appropriate navigational equipment and to transmit steering commands thereto, depending on the position of the machine and the required work route. Such control can only work precisely when the steering angles of the relevant steerable wheels used for directional control are known.
In this context, it is common practice to ascertain the steering angles during operation. Appropriate steering angle sensors can be, for example, potentiometers adapted to send different signals to a control or monitoring unit depending on the steering angle of the respective wheel.
It has been found that such steering angle sensors suffer from the drawback that they have a high tendency to failure. It has further been found that the results given by such steering angle sensors are not always unequivocal to a satisfactory degree.
It is thus an object of the present invention to provide a device and method for determining the steering angle of a steerable wheel of a set of steerable wheels of a machine that can be directionally controlled as described above, that make it possible to ascertain the steering angle of such a machine in a precise, inexpensive, and reliable manner.